Non-linear junction detector technology has previously been used to detect the presence of electronics connected to communication lines. The biggest limitation in previous non-linear junction detection methodologies is that the non-linear junction detection process was used only in a pass/fail capacity on lines that were believed to be completed isolated from electronic circuitry. Accordingly, prior art approaches were only able to determine if any electronics were present or coupled to a line under test if the line under test were disconnected from any normal and expected communication circuitry. For example, in order to detect concealed surveillance devices, technicians had to isolate a telephone line being tested from the local switch and from any attached phone sets or other electronic equipment to ensure that no known electronics were attached to the line. Unfortunately, disconnecting or removing all of the known electronics from a line being tested may be overly time consuming or difficult. Therefore, what is needed is a new and improved method and device for detecting electronics using non-linear junction detection while the line may still be connected to some communication equipment.